Hydrocarbons metals

Environment A number of melt water quality analyses of heavy metals, hydrocarbons, oxygen demands, and nutrients were made. From September 2001 to September 2002 measurements were made in the snow storage, in the stream where melt water is discharged and in the recipient, totally at seven locations. Reference measurements were made at a nearby location not affected by the outlet water. The results were compared with Swedish environmental quality criteria (SEPA, 1990 SEPA, 1999). 

Prior to 1985, decarboxylation of metal (hydrocarbon) arenedicarboxy-lates was restricted to mercury and to acids with two adjacent carboxylate groups. 

Combustion of powdered aluminum with steam is a potentially attractive propulsion system for torpedoes, because of the very high-energy density (energy per unit volume) that can be achieved. Since the oxidizer can be taken from the environment, on-board storage is required only for the aluminum propellant. A study of potential torpedo propellant/oxidizer combinations including Al, Zr, Mg, and Li metals, hydrocarbon fuels, and typical solid rocket propellants, and... 

This is one of two articles in this volume concerned with the borane-carborane structural pattern. In the other (see Williams, this volume, p. 67) Williams has shown how the pattern reflects the coordination number preferences of the various atoms involved. The purpose of the present article is to note some bonding implications of the pattern, and to show its relevance to a wide range of other compounds, including metal clusters, metal-hydrocarbon n complexes, and various neutral or charged hydrocarbons. 

Fig. 24. The nido structures of some metal-hydrocarbon tt complexes containing CnHfi ring systems.

Fig. 25. The arachno structures of some metal-hydrocarbon w complexes. (Carbonyl ligands not shown.)...

Arachno structures among main group metal-hydrocarbon complexes... 

Examples of reductive cluster-opening and oxidative cluster-closing reactions are common in the chemistry of metal-hydrocarbon tt complexes. For example, bases convert nido- (hexa-hapto)arene-manganese tricarbonyl complexes into aracAno(pentahapto)-7T-cyclohexadienyl complexes 129,130, 217) ... 

Wade expanded the 1971 hypothesis to incorporate metal hydrocarbon 7T complexes, electron-rich aromatic ring systems, and aspects of transition metal cluster compounds [a parallel that had previously been noted by Corbett 19) for cationic bismuth clusters]. Rudolph and Pretzer chose to emphasize the redox nature of the closo, nido, and arachno interconversions within a given size framework, and based the attendant opening of the deltahedron after reduction (diagonally downward from left to right in Fig. 1) on first- and second-order Jahn-Teller distortions 115, 123). Rudolph and Pretzer have also successfully utilized the author s approach to predict the most stable configuration of SB9H9 (1-25) 115) and other thiaboranes. 

Exchange reactions in HC/D2 mixtures. In particular, the bonding metal-hydrocarbon fragment is conveniently studied by these reactions. The basis of these studies has been established by Kemball (see, e.g., 158, 159), Burwell (e.g., 160), Tamaru (161), Bond (162), and others. 

This review deals with metal-hydrocarbon complexes under the following headings (1) the nature of the metal-olefin and -acetylene bond (2) olefin complexes (3) acetylene complexes (4) rr-allylic complexes and (5) complexes in which the ligand is not the original olefin or acetylene, but a molecule produced from it during complex formation. ir-Cyclopentadienyl complexes, formed by reaction of cyclopentadiene or its derivatives with metal salts or carbonyls (78, 217), are not discussed in this review, neither are complexes derived from aromatic systems, e.g., benzene, the cyclo-pentadienyl anion, and the cycloheptatrienyl cation (74, 78, 217), and from acetylides (169, 170), which have been reviewed elsewhere. 

Cycloheptatriene likewise gives the complex [Cr(CO)3(C7H8)] (VII R = H), in which all six -electrons of the triene are used in the metal-hydrocarbon bond (2). In the complex of 1-phenylcycloheptatriene the... 

Comprehensive coverage has not been attempted, but rather the intention has been to provide an introduction for the non-specialist which illustrates the scope of the field and highlights the main features of interest to organic chemists. Citation of all relevant publications is impracticable because of the large volume of literature. However, it is hoped that those key papers and specialist review articles which are included will enable the reader to locate related literature of interest. Advances in the chemistry of metallacycles and metal-hydrocarbon ir-complexes are thoroughly reviewed in surveys of organometallic chemistry published annually since 1972 (B-72MI12200). 

Finally the ESR spectrum of Nb(7r-allyl)4/alumina was unaffected by the addition of ethylene gas to the ESR sample tube. It is assumed that polyethylene is produced in this process since polymer can be isolated from larger scale reactions under similar conditions. The accepted mechanism for the ethylene growth reaction postulates a steady-state concentration of a a-bonded transition metal-hydrocarbon species which would be expected to modify the ESR spectrum of the supported complex. A possible explanation for the failure to detect a change in the ESR spectrum may be that only a small number of the niobium sites are active for polymerization. Although further experiments are needed to verify this proposition, it is consistent with IR data and radiochemical studies of similar catalyst systems (41, 42, 43). 

BuNa/TMEDA/hexane is comparable to BuLi/TMEDA. Thus it deprotonates weak organic acids. Benzylsodium-TMEDA (made from toluene) is obtained as yellow needles. BuK/TMEDA, prepared in the same way, metallates hydrocarbons more readily than BuNa/TMEDA, but also decomposes more readily.1... 

Metalloboranes Their Relationships to Metal-Hydrocarbon Complexes and Ousters, 21, 57 Metallocarboranes, Ten Years of, 14, 145 Methylene Bridge, 20, 159... 

Several workers have used this approach to metalate hydrocarbon polymers. Plate and co-workers (98), for example, metalated polystyrene and monitored the butane evolution by gas chromatography. They reported a 40% catalyst efficiency. However, they did not report the grafting efficiency or the overall effectiveness of this metalating reagent. 

During both Phases I and II, 71 piezometers were installed to monitor groundwater. A total of 221 water samples were collected and 9463 analyses were carried out. Seven field surveys sampled shallow and deep groundwater, analyzing various physicochemical parameters (e. g., pH, Eh, dissolved 02, temperature, conductivity), and the presence of potentially harmful elements and compounds (e.g., heavy metals, hydrocarbons, PAH). The hydrogeological survey carried out by the Bagnoli SpA, concluded that... 

Puromycin Cyclosporine A Penicillamine Heavy metals Hydrocarbons Colloidal gold/ gold salts NSAIDs Mitomycin C... 

The reaction is reversible. If a fluorinated olefin is used, it would be expected that the resulting fluoroalkyl compound would be readily obtained, since the greater strength of the metal-fluorocarbon bond as compared to the metal-hydrocarbon bond favors the insertion reaction 267). The reaction of hydroplatinum(II) complexes with fluoroolefins has been extensively studied. A surprising product from a number of these reactions is a fluorovinyl compound rather than the anticipated fluoroalkyl complex. In Fig. 4 are shown the reactions of PtHCl(PEt3)2 with a series of fluoroolefins to give PtCl(CF=CF2)(PEt3)2 (XXXIV)... 

Numerous synthetic organic and inorganic compounds, organochlorines, dioxins, heavy metals, hydrocarbons, chlorinated phenols, sulfates, sulfides, surfactants, solvents, acids, bases, salts, pharmaceuticals, plastics, resins, explosives, and natural organics Residential and commercial chemicals, pesticides, fertilizers, hydrocarbons, solvents, surfactants, paints, sealants, medicines, volatile organic compounds, resins, plastics, metals, salts, acids, and bases... 

A procedure better adapted to operation on a large scale is described by Bavin. A solution of 1 mole of fluorene in 500 ml. of ether is added with stirring under reflux to an ethereal solution of phenyllithium prepared from 1.5 moles of bromo-benzene. After 1 hr. more the orange solution of metallated hydrocarbon is poured as rapidly as possible into powdered dry ice which has been slurried with ether. The mixture is acidified, the solvent removed by steam distillation, and the solid is dissolved in aqueous potassium carbonate solutioa Clarification with Norit gives a pale yellow solution which is poured into excess 30% hydrochloric acid. The colorless, crystalline product on reaction with methanol and hydrogen chloride gave the pure methyl ester, m.p. 64-65°. The yield was generally over 70% and occasionally reached 90%. ... 

The evidence in the foregoing papers points to the way in which catalysts may be influenced by overlayers. There remains the question of what the active sites might be in, for example, reactions involving hydrogen. The next paper identifies a metal-hydrocarbon species as a possibility. 

Figure 1.4. Mixed metal-carbon cluster compounds (metal-hydrocarbon n complexes) ( denotes hypercarbons).

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